Turntable platter for record players

Abstract

A turntable platter for record players, consisting of two layers one of glass and one of plastic, lying one on top of the other. The plastic layer can be of a thermoplastic and/or thermosetting material such as polycarbonate, polyacrylic, polystyrene or the like. The glass guarantees flatness, rigidity and pleasant appearance of the platter, such features not always being obtainable from the already known metal platters, while the plastic, guarantees light weight associated with such material. The glass-plastic combination in the turntable platter represents considerable progress in the particular industrial field as it guarantees the absorption of spurious vibrations, and secondly, optimum sound reproduction quality. The glass and plastic layers can be joined together by means of adhesive or pushed together and can also be of different sizes and shapes. The turntable platter can be provided with an upper layer, preferably less than one micron thick, of conductive material.

We claim: 
     
       1. A turntable platter comprising: a base disk having a center of rotation, a lower surface and an upper surface, said disk being made of plastic and including inner and outer edges extending upwardly from said upper surface defining an annular trough therebetween, said disk having an outer peripheral edge extending lower than a plane containing said lower surface of said disk, said outer peripheral edge being transparent;   a glass layer member engaged with said upper surface of said disk in said annular trough and covering at least a portion of said top surface, said glass layer member being annular in shape and being positioned on an outer portion of said upper surface of said disk spaced away from said center of rotation, a portion of said upper surface of said disk adjacent said center of rotation being in a lower plane than a plane containing an upper surface of said glass layer member;   adhesive between said base disk and said glass layer member for connecting said glass layer member to said disk; and   an electrically conductive thin layer disposed on said upper surface of said glass layer and made of one of dielectric and metallic material and having a thickness which is less than micron.